Foreign material exclusion devices have been developed in order to minimize or prevent various materials or debris, which are not designed to be present in a construction or system, from adversely affecting the construction or system, especially during repair or maintenance. Examples of various foreign material exclusion devices are set forth for example in the following U.S. Patents and Publications.
U.S. Pat. No. 6,506,014 relates to a device which can be utilized to temporarily seal substantially any opening on a turbine which is being assembled or repaired. The foreign material exclusion device advantageously maintains fail-safe integrity of desired portions of a turbine. Protection of the sensitive areas of a turbine prevents possible hazardous malfunctions or explosions of a turbine. The foreign material exclusion device is substantially elastic or resilient and can be compressed to fit into a desired opening and can be re-expanded to provide a snug fit about an opening.
U.S. Pat. No. 6,824,356 relates to a device which can be utilized to temporarily seal substantially any opening on a turbine which is being assembled or repaired. The foreign material exclusion device includes a main body, preferably formed from a foamed polymer or rubber. The foreign material exclusion device is substantially elastic or resilient and can be compressed to fit into a desired opening and can be re-expanded to provide a snug fit about an opening. An extraction member is connected to the main body and is preferably utilized to remove the device from a portion of a cavity of a turbine.
U.S. Pat. No. 7,533,698 relates to a foreign material exclusion device which is adapted to be utilized in tubes, pipes, or the like to prevent entry of debris into a potentially sensitive area of an assembly, such as a turbine assembly utilized in a power plant. In one embodiment, the device is adapted to be connected to a non-moving portion of a rotary milling tool, such as the collet, before a milling operation to prevent milling debris from entering a sensitive portion of a tube or pipe. In a further embodiment, each device of the invention includes a unique identifier or identification element, such as a machine readable bar code or RFID (radio frequency identification) tag, to insure all devices utilized for a particular job are accounted for.
U.S. Patent Application Publication No. 2011/0169630 relates to a foreign material exclusion device adapted for use in a cavity of a system or construction, for example a tube, pipe, or the like, the device having a body that is adapted to seal a first side of the cavity from a second side of the cavity and prevent passage of debris past the body, the device further including a sensor operatively connected to the body and adapted to measure a property of the environment adjacent at least one surface of the device. Methods for utilizing the device to seal a portion of the cavity and to record, and preferably distribute, the data are also described.
An alternative method of sealing or closing a cavity is to utilize inflatable or pneumatically actuated devices such as balloons, bags, or diaphragms. While some inflatable airbags offer advantages such as having desirable strength and strong sealing ability, disadvantages exist. For example, loss of air pressure in an inflatable device can cause sealing failure which can allow debris to access a sensitive or undesired area. Additionally, inflatable devices, in some embodiments, have an edge radius in the area of contact with a surface of a cavity or construction that can retain debris that is difficult to observe and remove prior to device removal.